1. Field of the Invention
The present invention relates to a 3D (three dimensional) image display apparatus which is suitable to display a 3D image in a television, video display, computer monitor, or game machine.
2. Description of the Related Art
Conventionally, various methods have been attempted as a 3D image reproducing method of reproducing a 3D image. Particularly, a naked-eye stereopsis method with which the observer need not wear special eyeglasses or the like is considered promising as the next-generation image information presentation device because it can attain a 3D sense with a live feeling.
According to a general naked-eye stereopsis method, the observer recognizes a 3D image with a two-eye parallax method which presents a right-eye parallax image and left-eye parallax image independently to the corresponding eyes of the observer. To present parallax image information to the two eyes independently, an image display device and a directivity generator which directs image information from the image display device to the left and right eyes respectively are necessary. For example, in a lenticular method which is the most popular method as the naked-eye stereopsis method, a lentlcular lens array serves as the directivity generator and is combined with an image display device such as an LCD (Liquid Crystal Display) or PDP (Plasma Display Panel) to form a 3D image display device. The conventional naked-eye stereopsis method appears in various literatures and is known widely (non-patent reference 1).
With 3D image recognition with the two-eye parallax method, a contradiction occurs between a 3D image recognition position obtained by the focal point accommodative function of the eyes and that obtained by two-eye parallax. This often causes the observer to feel tired or somewhat different.
In recent years, a three-dimensional image producing method (3D image reproducing method) that is based on not only two-eye parallax but satisfies other 3D image sensing functions to give the live feeling more strongly has been proposed (patent references 1 to 3).
According to the method proposed by patent reference 1, a large number of small parallax images are presented in different directions at small angular pitches, so a plurality of parallax images enter the single eye of the observer. When the plurality of parallax images are presented to the single eye of the observer in this manner, focal point accommodation of the observer is guided to a 3D image position recognized by two-eye parallax to eliminate the contradiction in 3D image perception. Thus, the fatigue or sense of incompatibility of the observer is decreased.
Also, parallax variations (so-called motion parallax) with respect to the movement of the observation position of the observer can be expressed correctly to improve the quality of the 3D image totally. Such 3D display is called 3D display with a “super multi-view region” and is presented in various literatures (non-patent references 2 and 3).